Get a Numerical Eyeful With 5 Million Digits of Pi

The average person knows maybe the first five or six digits of pi, trailing off somewhere around 3.141592, and even those who tout their superior memorization of the number probably only have about 20 digits to show off at the cocktail party. In other words, we know it’s lengthy, but have you ever stopped to really consider just how many digits make up this figure? It’s almost...irrational. (There's a little dad/math joke for your entertainment.)

The Leibniz Institute for Astrophysics Potsdam has a page with the first 5 million digits of pi, organized into nice little 50 digit cubes that march on for 500 pages. It’s staggering to scroll down and take in the sheer number of numbers, and also entertaining to plug in your phone number, birth date or other numerically significant sequence to see if you digits are written into a famed mathematical ratio.

Rajveer Meena holds the Guinness World Record for most pi decimal places memorized. He set the record earlier this year, and recited 70,000 digits while blindfolded. It took nearly 10 hours.

There's a ton of videos on YouTube with people showing their incredible memorization skills, like this one of middle school student Benjamin Most, who kept beating his own record at his school's annual pi recitation contest.

March 14, the mathematic high holiday known as Pi Day, is right around the corner. To celebrate everyone's favorite irrational number, we've rounded up some gifts to help the math aficionados in your life—the ones who know that pi is the ratio of the circumference of a circle to its diameter—observe Pi Day in proper fashion.

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If Pi Day passed and you didn't eat a pi pie, did Pi Day even happen? This specially shaped baking pan makes the equivalent volume of a 9-inch round pan, but obviously has more surface area than a standard pan. Pi puns and extra crust? Sounds like a win-win dessert.

Definitely know your audience before gifting this head-scratcher of a clock. For some, the regular mental exercise to figure out the time would be a welcomed brain-teaser. For others, it could be a frustrating distraction. But, we think its namesake—it should be relatively easy to figure out which Albert it's referencing—would be a fan.

Ancient calculators make great toys when it comes to this colorful bead toy aimed at kids 2 and up. But once the young ones hit grade school, this specially marked abacus will help them visualize arithmetic while still seeing the equations listed out.

This coloring book takes nature's best mathematical patterns and turns them into a soothing adult coloring book. Take a break from studying math's interconnected worlds, and just connect pencil to paper for a bit.

This hands-on math game makes learning arithmetic engaging and entertaining, and can help kids 3–6 years old recognize units and solve basic additions and subtractions. These wooden letters come with three free apps that you pair with any iPad and most Samsung and Nexus tablets.

You saw the movie—now delve even deeper into the true stories of Katherine Johnson, Dorothy Vaughan, Mary Jackson, and the other African-American women who worked at NASA as "human computers" during the Space Race. Margot Lee Shetterly's best-seller reveals just how much ground-breaking work these brilliant mathematicians truly did, even while dealing with both gender discrimination and the Jim Crow era. And if you haven't seen the movie, stream it on HBO or purchase it here.

Make sure your head is in working order before trying to solve this riddle from TED-Ed, because it's a stumper.

Here's the scenario: You're an explorer who's just stumbled upon a trove of valuable coins in a remote dungeon. Each coin has a gold side and a silver side, each with an identical scorpion seal. The wizard who guards the coins agrees to let you have them, but he won't let you leave the room unless you separate the hoard into two piles with an equal number of coins with the silver side facing up in each. You've just counted the total number of silver-side-up coins—20—when the lights go out. In the dark, you have no way of knowing which half of a coin is silver and which half is gold. How do you divide the pile without looking at it?

As TED-Ed explains, the task is fairly easy to complete, no psychic powers required. All you need to do is remove any 20 coins from the pile at random and flip them over. No matter what combination of coins you choose, you will suddenly have a number of silver-side-up coins that's equal to whatever is left in the pile. If every coin you pulled was originally gold-side-up, flipping them would give you 20 more silver-side-up coins. If you chose 13 gold-side-up coins and seven of the silver-side coins, you'd be left with 13 silver coins in the first pile and 13 silver ones in your new stack after flipping it over.

The solution is simple, but the algebra behind it may take a little more effort to comprehend. For the full explanation and a bonus riddle, check out the video from TED-Ed below.